1. Field of the Invention
This invention relates to an exposure control apparatus of a camera, and particularly to an exposure control apparatus of a camera in which manual exposure setting and automatic exposure setting are selectively possible.
2. Description of the Prior Art
The exposure setting of a camera, namely, the setting of photographing conditions, may be divided broadly into manual exposure setting and automatic exposure setting. In the manual exposure setting, the shutter dial of the camera and the aperture preset ring of the picture-taking lens are operated by the operator, whereby the aperture value and shutter time during exposure are arbitrarily set. In the automatic exposure setting there exist a plurality of kinds of control systems in which the aperture value and/or the shutter time is automatically set on the basis of the brightness of an object to be photographed measured by the photometering device of the camera and is classified by the difference between automatically set exposure factors, namely, shutter priority automatic exposure control, aperture priority automatic exposure control, programmed automatic exposure control, etc.
Where use is made of a camera provided with the two functions of manual exposure setting and automatic exposure setting and capable of arbitrarily selecting one of the two functions by a change-over dial or the like, it is the usual practice for the operator to normally select the automatic exposure setting and take a number of photographs and to select the manual exposure setting when he wants to introduce a special intention into photography. This is just because the automatic exposure setting is simple in operation and can quickly cope with any change of the object to be photographed. In such a camera, when a situation in which other object must be urgently photographed has occurred while photography is being carried out with the manual exposure setting selected, if the brightness of the object so far photographed and the brightness of the new object differ greatly from each other, it has been necessary either to manually re-set the aperture and shutter time to render the exposure proper or to operate a change-over dial provided externally of the camera for the selection of the automatic exposure setting. For such operations, it has usually been necessary for the operator to once take his eye off the finder, and this has led to the impossibility of quickly coping with the new object and the undesirable possibility of missing the shutter chance.